We have a dual fuel GE 6B DLN1 combustion Turbine with MARKV controls. We have changed out the Servo on the liquid fuel bypass valve and want to check it if polarity is correct on the installation of the new servo. Is there a way to stroke this valve? We have it in "auto-calibration" page but no luck. We are able to stroke the SRV, CV, Splitter valve and IGV servos and perform the check of removing 2 out of 3 servo command currents. They work. The LFBV has no LVDT's or any means of showing position except for visible shaft movement.